Metal

Coprecipitation

Adsorption

Engineering

Mercury (programming language)

Pyrolysis

Materials science

Chromatography

Computer science

Inorganic chemistry

Chemical engineering

Mass transfer

Biochar

Organic chemistry

Doping

Desorption

Chemistry

Programming language

Charcoal

Optoelectronics

Bioresource Technology

An iron-based composite adsorbent with biochar as the support was prepared by coprecipitation and the sol–gel method. Both single-iron-based modified biochar without doping with other metals and iron-based modified biochar doped with multiple metals (Ce, Cu, Co, Mn) were synthesised. The adsorption kinetics were analysed, and temperature-programmed desorption measurements were performed to reveal the inherent difference in mechanism between the oxidation and adsorption of Hg0 by the modified biochar and to elucidate the key mechanism of Hg0 removal. The results show that the removal of Hg0 by the modified biochar mainly includes adsorption and oxidation processes. The adsorption process is divided into two stages, external and internal mass transfer, both of which occur via multilayer adsorption. HgO and Hg-OM are the main forms of Hg0 present on the modified biochar surface. Doped metal oxides can play a synergistic role in enhancing the mercury removal performance of the modified biochar.

Study on the Hg0 removal characteristics and synergistic mechanism of iron-based modified biochar doped with multiple metals